1/*
  2 * FPGA Manager Core
  3 *
  4 *  Copyright (C) 2013-2015 Altera Corporation
  5 *
  6 * With code from the mailing list:
  7 * Copyright (C) 2013 Xilinx, Inc.
  8 *
  9 * This program is free software; you can redistribute it and/or modify it
 10 * under the terms and conditions of the GNU General Public License,
 11 * version 2, as published by the Free Software Foundation.
 12 *
 13 * This program is distributed in the hope it will be useful, but WITHOUT
 14 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 15 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 16 * more details.
 17 *
 18 * You should have received a copy of the GNU General Public License along with
 19 * this program.  If not, see <http://www.gnu.org/licenses/>.
 20 */
 21#include <linux/firmware.h>
 22#include <linux/fpga/fpga-mgr.h>
 23#include <linux/idr.h>
 24#include <linux/module.h>
 25#include <linux/of.h>
 26#include <linux/mutex.h>
 27#include <linux/slab.h>
 28
 29static DEFINE_IDA(fpga_mgr_ida);
 30static struct class *fpga_mgr_class;
 31
 32/**
 33 * fpga_mgr_buf_load - load fpga from image in buffer
 34 * @mgr:	fpga manager
 35 * @flags:	flags setting fpga confuration modes
 36 * @buf:	buffer contain fpga image
 37 * @count:	byte count of buf
 38 *
 39 * Step the low level fpga manager through the device-specific steps of getting
 40 * an FPGA ready to be configured, writing the image to it, then doing whatever
 41 * post-configuration steps necessary.  This code assumes the caller got the
 42 * mgr pointer from of_fpga_mgr_get() and checked that it is not an error code.
 43 *
 44 * Return: 0 on success, negative error code otherwise.
 45 */
 46int fpga_mgr_buf_load(struct fpga_manager *mgr, u32 flags, const char *buf,
 47		      size_t count)
 48{
 49	struct device *dev = &mgr->dev;
 50	int ret;
 51
 52	/*
 53	 * Call the low level driver's write_init function.  This will do the
 54	 * device-specific things to get the FPGA into the state where it is
 55	 * ready to receive an FPGA image.
 56	 */
 57	mgr->state = FPGA_MGR_STATE_WRITE_INIT;
 58	ret = mgr->mops->write_init(mgr, flags, buf, count);
 59	if (ret) {
 60		dev_err(dev, "Error preparing FPGA for writing\n");
 61		mgr->state = FPGA_MGR_STATE_WRITE_INIT_ERR;
 62		return ret;
 63	}
 64
 65	/*
 66	 * Write the FPGA image to the FPGA.
 67	 */
 68	mgr->state = FPGA_MGR_STATE_WRITE;
 69	ret = mgr->mops->write(mgr, buf, count);
 70	if (ret) {
 71		dev_err(dev, "Error while writing image data to FPGA\n");
 72		mgr->state = FPGA_MGR_STATE_WRITE_ERR;
 73		return ret;
 74	}
 75
 76	/*
 77	 * After all the FPGA image has been written, do the device specific
 78	 * steps to finish and set the FPGA into operating mode.
 79	 */
 80	mgr->state = FPGA_MGR_STATE_WRITE_COMPLETE;
 81	ret = mgr->mops->write_complete(mgr, flags);
 82	if (ret) {
 83		dev_err(dev, "Error after writing image data to FPGA\n");
 84		mgr->state = FPGA_MGR_STATE_WRITE_COMPLETE_ERR;
 85		return ret;
 86	}
 87	mgr->state = FPGA_MGR_STATE_OPERATING;
 88
 89	return 0;
 90}
 91EXPORT_SYMBOL_GPL(fpga_mgr_buf_load);
 92
 93/**
 94 * fpga_mgr_firmware_load - request firmware and load to fpga
 95 * @mgr:	fpga manager
 96 * @flags:	flags setting fpga confuration modes
 97 * @image_name:	name of image file on the firmware search path
 98 *
 99 * Request an FPGA image using the firmware class, then write out to the FPGA.
100 * Update the state before each step to provide info on what step failed if
101 * there is a failure.  This code assumes the caller got the mgr pointer
102 * from of_fpga_mgr_get() and checked that it is not an error code.
103 *
104 * Return: 0 on success, negative error code otherwise.
105 */
106int fpga_mgr_firmware_load(struct fpga_manager *mgr, u32 flags,
107			   const char *image_name)
108{
109	struct device *dev = &mgr->dev;
110	const struct firmware *fw;
111	int ret;
112
113	dev_info(dev, "writing %s to %s\n", image_name, mgr->name);
114
115	mgr->state = FPGA_MGR_STATE_FIRMWARE_REQ;
116
117	ret = request_firmware(&fw, image_name, dev);
118	if (ret) {
119		mgr->state = FPGA_MGR_STATE_FIRMWARE_REQ_ERR;
120		dev_err(dev, "Error requesting firmware %s\n", image_name);
121		return ret;
122	}
123
124	ret = fpga_mgr_buf_load(mgr, flags, fw->data, fw->size);
125
126	release_firmware(fw);
127
128	return ret;
129}
130EXPORT_SYMBOL_GPL(fpga_mgr_firmware_load);
131
132static const char * const state_str[] = {
133	[FPGA_MGR_STATE_UNKNOWN] =		"unknown",
134	[FPGA_MGR_STATE_POWER_OFF] =		"power off",
135	[FPGA_MGR_STATE_POWER_UP] =		"power up",
136	[FPGA_MGR_STATE_RESET] =		"reset",
137
138	/* requesting FPGA image from firmware */
139	[FPGA_MGR_STATE_FIRMWARE_REQ] =		"firmware request",
140	[FPGA_MGR_STATE_FIRMWARE_REQ_ERR] =	"firmware request error",
141
142	/* Preparing FPGA to receive image */
143	[FPGA_MGR_STATE_WRITE_INIT] =		"write init",
144	[FPGA_MGR_STATE_WRITE_INIT_ERR] =	"write init error",
145
146	/* Writing image to FPGA */
147	[FPGA_MGR_STATE_WRITE] =		"write",
148	[FPGA_MGR_STATE_WRITE_ERR] =		"write error",
149
150	/* Finishing configuration after image has been written */
151	[FPGA_MGR_STATE_WRITE_COMPLETE] =	"write complete",
152	[FPGA_MGR_STATE_WRITE_COMPLETE_ERR] =	"write complete error",
153
154	/* FPGA reports to be in normal operating mode */
155	[FPGA_MGR_STATE_OPERATING] =		"operating",
156};
157
158static ssize_t name_show(struct device *dev,
159			 struct device_attribute *attr, char *buf)
160{
161	struct fpga_manager *mgr = to_fpga_manager(dev);
162
163	return sprintf(buf, "%s\n", mgr->name);
164}
165
166static ssize_t state_show(struct device *dev,
167			  struct device_attribute *attr, char *buf)
168{
169	struct fpga_manager *mgr = to_fpga_manager(dev);
170
171	return sprintf(buf, "%s\n", state_str[mgr->state]);
172}
173
174static DEVICE_ATTR_RO(name);
175static DEVICE_ATTR_RO(state);
176
177static struct attribute *fpga_mgr_attrs[] = {
178	&dev_attr_name.attr,
179	&dev_attr_state.attr,
180	NULL,
181};
182ATTRIBUTE_GROUPS(fpga_mgr);
183
184static int fpga_mgr_of_node_match(struct device *dev, const void *data)
185{
186	return dev->of_node == data;
187}
188
189/**
190 * of_fpga_mgr_get - get an exclusive reference to a fpga mgr
191 * @node:	device node
192 *
193 * Given a device node, get an exclusive reference to a fpga mgr.
194 *
195 * Return: fpga manager struct or IS_ERR() condition containing error code.
196 */
197struct fpga_manager *of_fpga_mgr_get(struct device_node *node)
198{
199	struct fpga_manager *mgr;
200	struct device *dev;
201	int ret = -ENODEV;
202
203	dev = class_find_device(fpga_mgr_class, NULL, node,
204				fpga_mgr_of_node_match);
205	if (!dev)
206		return ERR_PTR(-ENODEV);
207
208	mgr = to_fpga_manager(dev);
209	if (!mgr)
210		goto err_dev;
211
212	/* Get exclusive use of fpga manager */
213	if (!mutex_trylock(&mgr->ref_mutex)) {
214		ret = -EBUSY;
215		goto err_dev;
216	}
217
218	if (!try_module_get(dev->parent->driver->owner))
219		goto err_ll_mod;
220
221	return mgr;
222
223err_ll_mod:
224	mutex_unlock(&mgr->ref_mutex);
225err_dev:
226	put_device(dev);
227	return ERR_PTR(ret);
228}
229EXPORT_SYMBOL_GPL(of_fpga_mgr_get);
230
231/**
232 * fpga_mgr_put - release a reference to a fpga manager
233 * @mgr:	fpga manager structure
234 */
235void fpga_mgr_put(struct fpga_manager *mgr)
236{
237	module_put(mgr->dev.parent->driver->owner);
238	mutex_unlock(&mgr->ref_mutex);
239	put_device(&mgr->dev);
240}
241EXPORT_SYMBOL_GPL(fpga_mgr_put);
242
243/**
244 * fpga_mgr_register - register a low level fpga manager driver
245 * @dev:	fpga manager device from pdev
246 * @name:	fpga manager name
247 * @mops:	pointer to structure of fpga manager ops
248 * @priv:	fpga manager private data
249 *
250 * Return: 0 on success, negative error code otherwise.
251 */
252int fpga_mgr_register(struct device *dev, const char *name,
253		      const struct fpga_manager_ops *mops,
254		      void *priv)
255{
256	struct fpga_manager *mgr;
257	int id, ret;
258
259	if (!mops || !mops->write_init || !mops->write ||
260	    !mops->write_complete || !mops->state) {
261		dev_err(dev, "Attempt to register without fpga_manager_ops\n");
262		return -EINVAL;
263	}
264
265	if (!name || !strlen(name)) {
266		dev_err(dev, "Attempt to register with no name!\n");
267		return -EINVAL;
268	}
269
270	mgr = kzalloc(sizeof(*mgr), GFP_KERNEL);
271	if (!mgr)
272		return -ENOMEM;
273
274	id = ida_simple_get(&fpga_mgr_ida, 0, 0, GFP_KERNEL);
275	if (id < 0) {
276		ret = id;
277		goto error_kfree;
278	}
279
280	mutex_init(&mgr->ref_mutex);
281
282	mgr->name = name;
283	mgr->mops = mops;
284	mgr->priv = priv;
285
286	/*
287	 * Initialize framework state by requesting low level driver read state
288	 * from device.  FPGA may be in reset mode or may have been programmed
289	 * by bootloader or EEPROM.
290	 */
291	mgr->state = mgr->mops->state(mgr);
292
293	device_initialize(&mgr->dev);
294	mgr->dev.class = fpga_mgr_class;
295	mgr->dev.parent = dev;
296	mgr->dev.of_node = dev->of_node;
297	mgr->dev.id = id;
298	dev_set_drvdata(dev, mgr);
299
300	ret = dev_set_name(&mgr->dev, "fpga%d", id);
301	if (ret)
302		goto error_device;
303
304	ret = device_add(&mgr->dev);
305	if (ret)
306		goto error_device;
307
308	dev_info(&mgr->dev, "%s registered\n", mgr->name);
309
310	return 0;
311
312error_device:
313	ida_simple_remove(&fpga_mgr_ida, id);
314error_kfree:
315	kfree(mgr);
316
317	return ret;
318}
319EXPORT_SYMBOL_GPL(fpga_mgr_register);
320
321/**
322 * fpga_mgr_unregister - unregister a low level fpga manager driver
323 * @dev:	fpga manager device from pdev
324 */
325void fpga_mgr_unregister(struct device *dev)
326{
327	struct fpga_manager *mgr = dev_get_drvdata(dev);
328
329	dev_info(&mgr->dev, "%s %s\n", __func__, mgr->name);
330
331	/*
332	 * If the low level driver provides a method for putting fpga into
333	 * a desired state upon unregister, do it.
334	 */
335	if (mgr->mops->fpga_remove)
336		mgr->mops->fpga_remove(mgr);
337
338	device_unregister(&mgr->dev);
339}
340EXPORT_SYMBOL_GPL(fpga_mgr_unregister);
341
342static void fpga_mgr_dev_release(struct device *dev)
343{
344	struct fpga_manager *mgr = to_fpga_manager(dev);
345
346	ida_simple_remove(&fpga_mgr_ida, mgr->dev.id);
347	kfree(mgr);
348}
349
350static int __init fpga_mgr_class_init(void)
351{
352	pr_info("FPGA manager framework\n");
353
354	fpga_mgr_class = class_create(THIS_MODULE, "fpga_manager");
355	if (IS_ERR(fpga_mgr_class))
356		return PTR_ERR(fpga_mgr_class);
357
358	fpga_mgr_class->dev_groups = fpga_mgr_groups;
359	fpga_mgr_class->dev_release = fpga_mgr_dev_release;
360
361	return 0;
362}
363
364static void __exit fpga_mgr_class_exit(void)
365{
366	class_destroy(fpga_mgr_class);
367	ida_destroy(&fpga_mgr_ida);
368}
369
370MODULE_AUTHOR("Alan Tull <atull@opensource.altera.com>");
371MODULE_DESCRIPTION("FPGA manager framework");
372MODULE_LICENSE("GPL v2");
373
374subsys_initcall(fpga_mgr_class_init);
375module_exit(fpga_mgr_class_exit);